Spine

Clinical Manifestations

Most patients will present for evaluation of an asymmetric spine, which is usually pain free. A complete physical examination is necessary for any patient with a spinal deformity because the deformity can indicate an underlying disease. The back is examined from behind ( Fig. 202.1 ). First, the levelness of the pelvis is assessed. Leg-length discrepancy produces pelvic obliquity, which often results in compensatory scoliosis . When the pelvis is level, the spine is examined for symmetry and spinal curvature with the patient upright. Cutaneous lesions (hemangioma, skin dimple, or hair tuft) should be noted. The spine should be palpated for areas of tenderness.

The patient is then asked to bend forward with the hands directed between the feet ( Adams forward bend test ). The examiner should inspect for asymmetry in the spine. The presence of a thoracic prominence in this position is the hallmark for scoliosis. The area opposite the thoracic prominence is usually depressed because of spinal rotation. Scoliosis is a rotational malalignment of one vertebra on another, resulting in rib elevation in the thoracic spine and paravertebral muscle elevation in the lumbar spine. With the patient still in the forward flexed position, inspection from the side can reveal the degree of roundback. A sharp forward angulation in the thoracolumbar region indicates a kyphotic deformity . It is important to examine the skin for café-au-lait spots ( neurofibromatosis ), hairy patches, and nevi ( spinal dysraphism ). Abnormal extremities may indicate skeletal dysplasia, whereas heart murmurs can be associated with Marfan syndrome. It is essential to do a full neurologic examination to determine whether the scoliosis is idiopathic or secondary to an underlying neuromuscular disease, and to assess whether the scoliosis is producing any neurologic sequelae.

Radiologic Evaluation

Initial radiographs should include a posteroanterior and lateral standing film of the entire spine. The entire pelvis including iliac crests should be visible to help determine skeletal maturity. The degree of curvature is measured from the most tilted or end vertebra of the curve superiorly and inferiorly to determine the Cobb angle ( Fig. 202.2 ). Newer imaging modalities such as slot scanning (e.g., EOS) provide the ability to obtain accurate measurements with much lower radiation.

Idiopathic Scoliosis

Congenital Scoliosis

Abnormalities of the vertebral formation during the first trimester may lead to structural deformities of the spine that are evident at birth or early childhood. Congenital scoliosis can be classified as follows ( Fig. 202.3 ):

• Partial or complete failure of vertebral formation (wedge vertebra or hemivertebra)

• Partial or complete failure of segmentation (unsegmented bars)

• Mixed

More than 60% of patients have other associated abnormalities, such as VACTERL association (vertebral defects, imperforate anus, cardiac anomalies, tracheoesophageal fistula, renal anomalies, limb abnormalities such as radial agenesis) or Klippel-Feil syndrome. Renal anomalies occur in 20–40% of children with congenital scoliosis, with renal agenesis being the most common; 6% of children have a silent, obstructive uropathy suggesting the need for evaluation with ultrasonography. Congenital heart disease occurs in about 12% of patients. Spinal dysraphism (tethered cord, intradural lipoma, syringomyelia, diplomyelia, and diastematomyelia) occurs in approximately 20% of children with congenital scoliosis. These disorders are frequently associated with cutaneous lesions on the back and abnormalities of the legs and feet (e.g., cavus foot, neurologic changes, calf atrophy). MRI is indicated in evaluation of spinal dysraphism.

The risk of spinal deformity progression in congenital scoliosis is variable and depends on the growth potential of the malformed vertebrae. A unilateral unsegmented bar typically progresses, but a block vertebra has little growth potential. About 75% of patients with congenital scoliosis will show some progression that continues until skeletal growth is complete, and about 50% will require some type of treatment. Progression can be expected during periods of rapid growth (<2 years and >10 years).

Treatment of congenital scoliosis hinges on early diagnosis and identification of progressive curves. Orthotic treatment is not helpful in congenital scoliosis. Early spinal surgery should be performed once progression has been documented. This can help prevent major deformities. Patients with large curves that cause thoracic insufficiency should undergo surgery immediately.

Neuromuscular Scoliosis

Progressive spinal deformity is a common and potentially serious problem associated with many neuromuscular disorders, such as cerebral palsy, Duchenne muscular dystrophy, spinal muscular atrophy, and spina bifida. Spinal alignment must be part of the routine examination for a patient with neuromuscular disease. Once scoliosis begins, progression is usually continuous. The magnitude of the deformity depends on the severity and pattern of weakness, whether the underlying disease process is progressive, and the amount of remaining musculoskeletal growth. Nonambulatory patients have a higher incidence of spinal deformity than ambulatory patients. In nonambulatory patients, the curves tend to be long and sweeping, produce pelvic obliquity, involve the cervical spine, and also produce restrictive lung disease. If the child cannot stand, then a supine or seated anteroposterior radiograph of the entire spine, rather than a standing posteroanterior view, is indicated.

The goal of treatment is to prevent progression and loss of function. Nonambulatory patients are more comfortable and independent when they can sit in a wheelchair without external support. Progressive curves can impair sitting balance, which affects quality of life. Pulmonary dysfunction may be seen as collapse of the spine, which causes the pelvis to impinge on the rib cage. Orthotic treatment is usually ineffective in neuromuscular scoliosis. Surgical intervention may be necessary with frequent fusion to the pelvis.

Compensatory Scoliosis

Adolescents with a leg-length discrepancy (see Chapter 200 ) may have a positive screening examination for scoliosis. Before correction of the pelvic obliquity, the spine curves in the same direction as the obliquity. However, with identification and correction of any pelvic obliquity, the curvature should resolve, and treatment should be directed at the leg-length discrepancy. Thus, it is important to distinguish between a structural and compensatory spinal deformity.